Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Glutamate receptors of Drosophila melanogaster: cloning of a kainate-selective subunit expressed in the central nervous system.

ABSTRACT: We report the isolation and functional characterization of cDNAs encoding a Drosophila kainate-selective glutamate receptor. The deduced mature 964-residue protein (DGluR-I) is 108,482 Da and exhibits significant homology to mammalian glutamate receptor subunits. Injection of DGluR-I cRNA into Xenopus oocytes generated kainate-operated ion channels which were blocked by the selective non-N-methyl-D-aspartate receptor antagonist 6-cyano-7-nitro-quinoxaline-2,3-dione and philanthotoxin. DGluR-I transcripts are differentially expressed during Drosophila development and, in late embryogenesis, accumulate in the central nervous system.

SUBMITTER: Ultsch A

PROVIDER: S-EPMC50363 | biostudies-other | 1992 Nov

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Glutamate receptors of Drosophila melanogaster: cloning of a kainate-selective subunit expressed in the central nervous system.

Ultsch A A Schuster C M CM Laube B B Schloss P P Schmitt B B Betz H H

Proceedings of the National Academy of Sciences of the United States of America 19921101 21

We report the isolation and functional characterization of cDNAs encoding a Drosophila kainate-selective glutamate receptor. The deduced mature 964-residue protein (DGluR-I) is 108,482 Da and exhibits significant homology to mammalian glutamate receptor subunits. Injection of DGluR-I cRNA into Xenopus oocytes generated kainate-operated ion channels which were blocked by the selective non-N-methyl-D-aspartate receptor antagonist 6-cyano-7-nitro-quinoxaline-2,3-dione and philanthotoxin. DGluR-I tr ...[more]

PMID: 1359540

Similar Datasets

A transmembrane accessory subunit that modulates kainate-type glutamate receptors.

Project description:Glutamate receptors play major roles in excitatory transmission in the vertebrate brain. Among ionotropic glutamate receptors (AMPA, kainate, NMDA), AMPA receptors mediate fast synaptic transmission and require TARP auxiliary subunits. NMDA receptors and kainate receptors play roles in synaptic transmission, but it remains uncertain whether these ionotropic glutamate receptors also have essential subunits. Using a proteomic screen, we have identified NETO2, a brain-specific protein of unknown function, as an interactor with kainate-type glutamate receptors. NETO2 modulates the channel properties of recombinant and native kainate receptors without affecting trafficking of the receptors and also modulates kainate-receptor-mediated mEPSCs. Furthermore, we found that kainate receptors regulate the surface expression of NETO2 and that NETO2 protein levels and surface expression are decreased in mice lacking the kainate receptor GluR6. The results show that NETO2 is a kainate receptor subunit with significant effects on glutamate signaling mechanisms in brain.

| S-EPMC2803770 | biostudies-literature

Functional reconstitution of Drosophila melanogaster NMJ glutamate receptors.

Project description:The Drosophila larval neuromuscular junction (NMJ), at which glutamate acts as the excitatory neurotransmitter, is a widely used model for genetic analysis of synapse function and development. Despite decades of study, the inability to reconstitute NMJ glutamate receptor function using heterologous expression systems has complicated the analysis of receptor function, such that it is difficult to resolve the molecular basis for compound phenotypes observed in mutant flies. We find that Drosophila Neto functions as an essential component required for the function of NMJ glutamate receptors, permitting analysis of glutamate receptor responses in Xenopus oocytes. In combination with a crystallographic analysis of the GluRIIB ligand binding domain, we use this system to characterize the subunit dependence of assembly, channel block, and ligand selectivity for Drosophila NMJ glutamate receptors.

| S-EPMC4434721 | biostudies-literature

Interface interactions modulating desensitization of the kainate-selective ionotropic glutamate receptor subunit GluR6.

Project description:Ionotropic glutamate receptors from the AMPA and kainate subfamilies share many functional and structural features, but it is unclear whether this similarity extends to the molecular mechanisms underlying receptor desensitization. The current model for desensitization in AMPA receptors involves the rearrangement of dimers formed between subunit agonist binding domains. Key evidence for this has come from a single point mutant (from leucine to tyrosine) that abolished desensitization and that was shown to stabilize the binding domain dimer. However, the desensitization of kainate receptors appears to differ from that of AMPA receptors in several key respects. Although the kinetics of AMPA receptor gating and desensitization are consistent with channels formed from two dimers, similar evidence for the functional involvement of dimers has not been found in kainate receptors. Furthermore, despite the homolog of the nondesensitizing tyrosine in AMPA subunits also being a tyrosine in wild-type kainate subunits, these receptors desensitize rapidly and completely. Using mutagenesis based on the crystal structure of the glutamate receptor subunit GluR6 S1S2 domain in complex with domoate, we identified four residues neighboring this tyrosine that differ between AMPA and kainate subunits and that contribute to the different desensitization kinetics of these receptors. Detailed analysis of the effects of mutations at these sites confirms that there is in fact a common general mechanism for desensitization in non-NMDA receptors, dependent on the stability of the binding domain dimer interface, and reveals the existence of potential agonist-specific desensitization pathways.

| S-EPMC6674465 | biostudies-literature

Activation of group I metabotropic glutamate receptors potentiates heteromeric kainate receptors.

Project description:Kainate receptors (KARs), a family of ionotropic glutamate receptors, are widely expressed in the central nervous system and are critically involved in synaptic transmission. KAR activation is influenced by metabotropic glutamate receptor (mGlu) signaling, but the underlying mechanisms are not understood. We undertook studies to examine how mGlu modulation affects activation of KARs. Confocal immunohistochemistry of rat hippocampus and cultured rat cortex revealed colocalization of the high-affinity KAR subunits with group I mGlu receptors. In hippocampal and cortical cultures, the calcium signal caused by activation of native KARs was potentiated by activation of group I mGlu receptors. In Xenopus laevis oocytes, activation of group I mGlu receptors potentiated heteromeric but not homomeric KAR-mediated currents, with no change in agonist potency. The potentiation of heteromeric KARs by mGlu1 activation was attenuated by GDPβS, blocked by an inhibitor of phospholipase C or the calcium chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), prolonged by the phosphatase inhibitor okadaic acid, but unaffected by the tyrosine kinase inhibitor lavendustin A. Protein kinase C (PKC) inhibition reduced the potentiation by mGlu1 of GluK2/GluK5, and conversely, direct activation of PKC by phorbol 12-myristate,13-acetate potentiated GluK2/GluK5. Using site-directed mutagenesis, we identified three serines (Ser833, Ser836, and Ser840) within the membrane proximal region of the GluK5 C-terminal domain that, in combination, are required for mGlu1-mediated potentiation of KARs. Together, these data suggest that phosphorylation of key residues in the C-terminal domain changes the overall charge of this domain, resulting in potentiated agonist responses.

| S-EPMC3533475 | biostudies-literature

Glutamate receptors on myelinated spinal cord axons: I. GluR6 kainate receptors.

Project description:ObjectiveThe deleterious effects of glutamate excitotoxicity are well described for central nervous system gray matter. Although overactivation of glutamate receptors also contributes to axonal injury, the mechanisms are poorly understood. Our goal was to elucidate the mechanisms of kainate receptor-dependent axonal Ca(2+) deregulation.MethodsDorsal column axons were loaded with a Ca(2+) indicator and imaged in vitro using confocal laser-scanning microscopy.ResultsActivation of glutamate receptor 6 (GluR6) kainate receptors promoted a substantial increase in axonal [Ca(2+)]. This Ca(2+) accumulation was due not only to influx from the extracellular space, but a significant component originated from ryanodine-dependent intracellular stores, which, in turn, depended on activation of L-type Ca(2+) channels: ryanodine, nimodipine, or nifedipine blocked the agonist-induced Ca(2+) increase. Also, GluR6 stimulation induced intraaxonal production of nitric oxide (NO), which greatly enhanced the Ca(2+) response: quenching of NO with intraaxonal (but not extracellular) scavengers, or inhibition of neuronal NO synthase with intraaxonal Nomega-nitro-L-arginine methyl ester, blocked the Ca(2+) increase. Loading axons with a peptide that mimics the C-terminal PDZ binding sequence of GluR6, thus interfering with the coupling of GluR6 to downstream effectors, greatly reduced the agonist-induced axonal Ca(2+) increase. Immunohistochemistry showed GluR6/7 clusters on the axolemma colocalized with neuronal NO synthase and Ca(v)1.2.InterpretationMyelinated spinal axons express functional GluR6-containing kainate receptors, forming part of novel signaling complexes reminiscent of postsynaptic membranes of glutamatergic synapses. The ability of such axonal "nanocomplexes" to release toxic amounts of Ca(2+) may represent a key mechanism of axonal degeneration in disorders such as multiple sclerosis where abnormal accumulation of glutamate and NO are known to occur.

| S-EPMC2902553 | biostudies-literature

Cloning and characterization of a receptor-class phosphotyrosine phosphatase gene expressed on central nervous system axons in Drosophila melanogaster.

Project description:We have cloned and characterized cDNAs coding for a receptor-class phosphotyrosine phosphatase gene from Drosophila melanogaster. The gene maps to the polytene chromosome bands 99A7-8. The cDNA clones code for a polypeptide of 1301 amino acids with a predicted molecular mass of 145 kDa. The extracellular domain includes two fibronectin-type III-like domains. The cytoplasmic region contains two tandemly repeated phosphotyrosine phosphatase-like domains. Residues shown crucial for catalytic activity are absent in the second domain. This Drosophila receptor-class phosphotyrosine phosphatase polypeptide is expressed on axons of the embryonic central nervous system.

| S-EPMC53115 | biostudies-other

Functional partnership between mGlu3 and mGlu5 metabotropic glutamate receptors in the central nervous system.

Project description:mGlu5 receptors are involved in mechanisms of activity-dependent synaptic plasticity, and are targeted by drugs developed for the treatment of CNS disorders. We report that mGlu3 receptors, which are traditionally linked to the control of neurotransmitter release, support mGlu5 receptor signaling in neurons and largely contribute to the robust mGlu5 receptor-mediated polyphosphoinositide hydrolysis in the early postnatal life. In cortical pyramidal neurons, mGlu3 receptor activation potentiated mGlu5 receptor-mediated somatic Ca2+ mobilization, and mGlu3 receptor-mediated long-term depression in the prefrontal cortex required the endogenous activation of mGlu5 receptors. The interaction between mGlu3 and mGlu5 receptors was also relevant to mechanisms of neuronal toxicity, with mGlu3 receptors shaping the influence of mGlu5 receptors on excitotoxic neuronal death. These findings shed new light into the complex role played by mGlu receptors in physiology and pathology, and suggest reconsideration of some of the current dogmas in the mGlu receptor field.

| S-EPMC6263139 | biostudies-literature

Interdomain interactions in AMPA and kainate receptors regulate affinity for glutamate.

Project description:Ionotropic glutamate receptors perform diverse functions in the nervous system. As a result, multiple receptor subtypes have evolved with different kinetics, ion permeability, expression patterns, and regulation by second messengers. Kainate receptors show slower recovery from desensitization and have different affinities for agonists than AMPA receptors. Based on analysis of ligand binding domain crystal structures, we identified interdomain interactions in the agonist-bound state that are conserved in kainate receptors and absent in AMPA receptors. Mutations in GluR6 designed to disrupt these contacts reduced agonist apparent affinity, speeded up receptor deactivation and increased the rate of recovery from desensitization. Conversely, introduction of mutations in GluR2 that enabled additional interdomain interactions in the agonist-bound state increased agonist apparent affinity 15-fold, and slowed both deactivation and recovery from desensitization. We conclude that interdomain interactions have evolved as a distinct mechanism that contributes to the unique kinetic properties of AMPA and kainate receptors.

| S-EPMC6674271 | biostudies-literature

Parkin regulates kainate receptors by interacting with the GluK2 subunit.

Project description:Although loss-of-function mutations in the PARK2 gene, the gene that encodes the protein parkin, cause autosomal recessive juvenile parkinsonism, the responsible molecular mechanisms remain unclear. Evidence suggests that a loss of parkin dysregulates excitatory synapses. Here we show that parkin interacts with the kainate receptor (KAR) GluK2 subunit and regulates KAR function. Loss of parkin function in primary cultured neurons causes GluK2 protein to accumulate in the plasma membrane, potentiates KAR currents and increases KAR-dependent excitotoxicity. Expression in the mouse brain of a parkin mutant causing autosomal recessive juvenile parkinsonism results in GluK2 protein accumulation and excitotoxicity. These findings show that parkin regulates KAR function in vitro and in vivo, and suggest that KAR upregulation may have a pathogenetic role in parkin-related autosomal recessive juvenile parkinsonism.

| S-EPMC4218952 | biostudies-literature

Mapping the ligand binding sites of kainate receptors: molecular determinants of subunit-selective binding of the antagonist [3H]UBP310.

Project description:Kainate receptors (KARs) modulate synaptic transmission and plasticity, and their dysfunction has been linked to several disease states such as epilepsy and chronic pain. KARs are tetramers formed from five different subunits. GluK1-3 are low affinity kainate binding subunits, whereas GluK4/5 bind kainate with high affinity. A number of these subunits can be present in any given cell type, and different combinations of subunits confer different properties to KARs. Here we report the characterization of a new GluK1 subunit-selective radiolabeled antagonist (S)-1-(2-amino-2-carboxyethyl)-3-(2-carboxythiophene-3-yl-methyl)-5-methylpyrimidine-2,4-dione ([(3)H]UBP310) using human recombinant KARs. [(3)H]UBP310 binds to GluK1 with low nanomolar affinity (K(D) = 21 ± 7 nM) but shows no specific binding to GluK2. However, [(3)H]UBP310 also binds to GluK3 (K(D) = 0.65 ± 0.19 ?M) but with ~30-fold lower affinity than that observed for GluK1. Competition [(3)H]UBP310 binding experiments on GluK1 revealed the same rank order of affinity of known GluK1-selective ligands as reported previously in functional assays. Nonconserved residues in GluK1-3 adjudged in modeling studies to be important in determining the GluK1 selectivity of UBP310 were point-mutated to switch residues between subunits. None of the mutations altered the expression or trafficking of KAR subunits. Whereas GluK1-T503A mutation diminished [(3)H]UBP310 binding, GluK2-A487T mutation rescued it. Likewise, whereas GluK1-N705S/S706N mutation decreased, GluK3-N691S mutation increased [(3)H]UBP310 binding activity. These data show that Ala487 in GluK2 and Asn691 in GluK3 are important determinants in reducing the affinity of UBP310 for these subunits. Insights from these modeling and point mutation studies will aid the development of new subunit-selective KAR antagonists.

| S-EPMC2993462 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data